The present invention relates generally to optical systems and, more particularly, to a generic centralized architecture for software-defined networking with latency one-way bypass communication.
In conventional optical network architectures, a protocol stack is employed such that data flows up and down the networking protocol layers. This bidirectional communication occurs in terms of hops from one layer to the next (above or below), and data has to be processed by special interfaces at every intermediate level. This happens since every protocol has its own special role to play, but also has rules for carrying data/processing/forwarding data. A case in point is today's Internet which employs such a protocol stack with each of the half dozen or so protocols performing certain functions. However, since communication on the Internet is based on packet switching, each of these packets requires a series of data encapsulations that are performed by the protocol layers. The resulting multi-layer protocol configuration incurs processing and queuing delays at every intermediate step. Moreover, even beyond this specific context of packet-switched communication of the Internet, multiple hops generally translate to delay at every interfacing step, which can be prohibitive for emerging low-latency applications/services.
Several previous approaches have been proposed based on bypassing, or skipping, layers in the networking protocol stack in order to reduce latency. For example, Internet Protocol (IP) over Wavelength Division Multiplexing (WDM), or IPoWDM for short, is well-established concept where the IP layer lies directly above the WDM layer, skipping all intermediate layers. More recently, in another prior work, the authors exploited software-defined centralized network control using an OpenFlow-based type of solution to control optical crossconnects (OXCs), and compared this with a centralized generalized multiprotocol label switching (GMPLS)-based solution where handshaking between peer entities takes place so as to reserve the network resources. By enabling parallel centralized control, the OpenFlow-based solution showed superior performance. Finally, in another prior work, a field trial demonstration was performed showing that a communication path between the IP layer directly to the WDM layer and then again to the IP layer can be established in a software-defined way using Open-Flow to configure all elements regardless of the layer they belong to. Apart from unifying network elements from different layers this was also an example of layer bypassing (skipping of unnecessary intermediate interfacing steps).
Accordingly, there is a need for a generic centralized, software-defined networking architecture for connecting network entities that overcomes the protocol and topology specific limitations of previous work